Dividing rolled lengths of stock into merchant lengths

ABSTRACT

In order to provide merchant lengths from a rolled length of stock, the stock is initially divided into lengths which are a multiple of a merchant length, the multiple lengths are cooled and batched, and the batches are then divided into merchant lengths. As the total rolled length will not be an integral multiple of a merchant length, there will usually be a discard length. In order to make it easy to remove the discard length mechanically, the method is carried out so that the rolled length of stock is divided into a number of integral multiple lengths of a merchant length together with a last multiple length which is an integral multiple of a merchant length plus a discard length and is longer by the discard length than the longest integral multiple length in the respective batch.

United States Patent 11 1 Giitlbauer et al.

llll 3,841,180

[451 Oct. 15,1974

1 1 DIVIDING ROLLED LENGTHS OF STOCK INTO MERCHANT LENGTHS [75] Inventors: Franz Giitlbauer, Essen; Meinert Meyer, Dusseldorf; Claus-Georg Schlanzke, Ratingen-Tiefenbroich, all of Germany [73] Assignee: Schloemann Aktiengesellschaft,

Steinstrasse, Germany [22] Filed: Oct. 1, 1973 [21] Appl. No.: 402,015

[30] Foreign Application Priority Data Sept. 30, 1972 Germany 2248177 [52]. US. Cl... 83/15, 83/112, 83/158,

83/288, 83/301, 83/404 [51] Int. Cl 823d 25/12, B23d 31/00 [58] Field of Search 83/15, 170, 288, 293, 301, 83/303, 369, 404, 158460, 112

[56] References Cited UNITED STATES PATENTS 9/1964 Fish et al. 83/288 Primary ExaminerJ. M. Meister Attorney, Agent, or Firm-Holman & Stern 5 7 ABSTRACT In order to provide'merchant lengths from a rolled length of stock, the stock is initially divided into lengths which are a multiple of a merchant length, the multiple lengths are cooled and batched, and the batches are then divided into merchant lengths. As the total rolled length will not be an integral multiple of a merchant length, there will usually be a discard length. In order to make it easy to remove the discard length mechanically, the method is carried out so that the rolled length of stock is divided into a number of integral multiple lengths of a merchant length together with a last multiple length which is an integral multiple of a merchant length plus a discard length and is longer by the discard length than the longest integral multiple length in the respective batch.

. 4 Claims, 3 Drawing Figures Fmimiunm 5m DIVIDING ROLLED LENGTHS OF STOCK INTO MERCHANT LENGTHS BACKGROUND OF THE INVENTION The invention relates to a method of dividing rolled lengths of stock (which may be of any suitable section) into merchant lengths. The rolled lengths of stock are initially divided into integral multiple lengths of the merchant lengths (such multiple lengths may be termed part-lengths) prior to being cooled in a cooling bed, with due reference to the maximum and minimum lengths permitted by the cooling bed and with reference to the total length of each length of stock as measured and computed, a plurality of multiple lengths are batched together, and each batch is divided into merchant lengths.

In the method described in Klepzig Fachberichte 80 (1972), pages 104/108, prior to dividing the rolled lengths into order lengths or merchant lengths, they are subdivided upstream of the cooling bed into such multiple lengths as give optimum utilizationof the cooling bed; thus discard lengths are obtained when the multiple lengths are subdivided by cold shears or saw at-a position downstream of the cooling bed.

However, it is impossible to avoid an unsaleable discard length being yielded from the last multiple length when the whole rolled length is subdivided. The discard lengths must then be awkwardly separated by manual means from the merchant lengths of, if they remain in a bundle of merchant lengths, the price per weight of the bundle mustbe correspondingly reduced. Manual sorting not only requires an operator but also takes additional time so that output is reduced. In some plants, in order to avoid this, the last multiple length is cut off together with the short discard length, upstream'of the cooling bed, and is supplied for further processing to'a discard trimming device. However, this procedure is also awkward and moreover calls for additional apparatus.

Attempts have also been made to permit discard-free cutting by the saw through precise predetermination of the charge length or charge weight of the billets. These attempts failed because of the difficulties encountered when attempting to eliminate effects, during rolling, of temperature difierences, groove wear, scale and the like on the length of the finished rolled length of stock.

DESCRIPTION OF THE INVENTION According to the invention, at least the last multiple length from the whole rolled length of stock is made longer by a-discard length than the longest integral multiple length within a batch-for cold shearing; if desired, the discard length of a whole rolled length of stock may be distributed over two multiple lengths.

The method presupposes that the length of the cooling bed is longer by approximately one merchant length than the maximum permissible'integral multiple length so that the calculated discard length can be added to the longest integral multiple length.

The method of the invention ensuresthat when the multiple lengths, which are delivered together in batches, are subsequently divided into merchant lengths, the discard lengths are cropped off last and can be easily ejected transversely to the delivery table.

The charge weight of the billet must form the basisfor calculating the discard length. This weight can be supplied to a computer which calculates the total rolled length by reference to the initial and final crosssections and controls shears which are disposed upstream of the cooling bed in such a way that the rolled length of stock, whose length is precalculated, is subdivided into integers of multiple lengths of the merchant lengths; the multiple lengths from one total rolled length can be of different magnitude with respect to each other as well with respect to those of a different total rolled length. Due allowance must be made for the fact that the multiple lengths may vary only within the maximum and minimum lengths which are to be delivered to the cooling bed, the longest integral multiple length having to be smaller than the length of the cooling bed by the amount of one merchant length.

Since the discard length or the total rolled length can only be theoretically precalculated, it is necessary to take into account any changes of length which might occur in practice. These changes may be the result of errors in defining the charge weight of the billet or they may be due to variations in the amount of scale and cropping end lengths or they may be due to crosssectional changes which in turn are the result of groove wear and temperature differences in the rolled stock. The length changes which result from these variables may amount to up to 15 m under unfavorable conditions, given a billet charge weight of 1,000 kg and a finished diameter for the rolled stock of 12 mm. In order to detect these differences by check measurements, to enablethem to be taken into account during the subdividing operation, the last but one or the last but one and the last but two multiple lengths may be made shorter by one or more merchant lengths than the maximum integral multiple length within one batch, and the end of each rolled le'ngth of stock maybe-sensed prior to cutting off said last but one or said last but one and last but two multiple lengths, said sensing being used to calculate the deviation of the actual rolled lengthfrom the calculated rolled length, such deviation being used to re-calculate the lengths of saidlast but one or said last but one and last. but two multiple lengths when they are cut off.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION 0F. PREFERRED EMBODIMENT A bar-2 is discharged from a last rollstand 1, and is subdivided by flying'shears 3,into multiple lengths which are then supplied to a run-up roller table 4 on which they are, decelerated in a conventional manner;

The multiple lengths are then passed through a cooling bed 5 and at the end thereof are collected on a delivery roller table 6 in batches corresponding to the usable width of the roller table 6; thebatches are supplied to cold shears or a cold saw7 for subdividing into merchant lengths.

A-measuring position 8, incorporating a photocell in a conventional manner, is disposed upstream of the flying shears 3 and signals the passage of the leading bar end to a computer 9. The bar velocity is transferred to the computer 9 in a conventional manner, for example by means of a tachometer 12 which is mounted on the last rollstand l and takes into account the roll diameter and the final cross-section of the bar. The computer 9 has already precalculated the optimum multiple lengths and the prospective discard lengths before the rolled bar has been fed in, namely from the charge weight and by taking into account the preceding and following rolled bars, the specified merchant length and the minimum and maximum permissible lengths in the cooling bed. The computer 9 controls the shears 3 via a pulse transmitter 11 in such a way that the total rolled length is subdivided into the calculated multiple lengths. The discard length is included in the last multiple length, which is also the longest length.

In order to allow for deviations from the calculated total rolled length when the rolled bar is subdivided, the multiple lengths are appropriately pre-calculated on the basis that the multiple length preceding the last multiple length or the two multiple lengths preceding the last multiple length will be cut shorter by one or more merchant lengthsthan the maximum multiple length; in this manner the said two multiple lengths may actually be cut even shorter than the pre-calculated length or longer than the pre-calculated length by one or more merchant lengths. To this end it is necessary that the rolled bar length, calculated on the basis of the billet charge weight, is once again sensed prior to the last multiple length cuts. This may be done by detectors which are disposed at a sufficient distance from the shears in the rolling train and which determine by check measurements any deviations from the precalculated rolled bar length and transmit the value to the computer 9. The computer 9 is then able to subsequently distribute the length deviations from the precalculated rolled bar length as determined by the check measurement over the two shortened multiple lengths which precede the last length. Depending on the magnitude of the deviation, one or more merchant lengths will be subtracted from the multiple lengths for a negative deviation and will be added thereto for a positive deviation. a

FIG. 1 shows by reference to three examples the manner in which length deviations from the calculated rolled bar length, caused by different rolling conditions, are distributed over the individual multiple lengths.

The pre-calculation for bar No. I initially indicated that the first multiple length must be cut shorter than the maximum multiple length by one merchant length while the subsequent multiple lengths with the exception of the two multiple lengths preceding the last length may have the maximum length. Check measurements then found that the rolled bar was longer by two merchant lengths than it should be on the basis'of the charge weight and final cross-section. Accordingly, the two multiple lengths preceding the last multiple length were also cut to the maximum length.

lnthe case of bar No.2, check measurement yields a negative deviation from the calculated length by approximately one merchant length. The multiple length preceding the last length therefore had to be cut shorter than the maximum permissible length X,,,,,,' VL by two merchant lengths VL so that the last multi ple length X VL discard length RL together become longer than the maximum multiple length X VL permitted by the cooling bed (this is possible be cause the discard length can overhang'in the cooling bed and the maximum length permitted by the cooling bed is greater than the maximum integral multiple length permitted by the cooling bed).

FIG. 2 shows how the multiple lengths of the bar No. 2 are disposed upstream of the shears 7 and the discard length RL remains on the last length of the total rolled bar length after cutting off all the merchant lengths. The discard length in this case can be easily pulled to one side either manually or by an automatically actuated pusher.

FIG. 3 shows the manner in which the computer 9 operates in conjunction with cold shearing batches which have different maximum multiple lengths. The input constants may for example be defined as follows:

The computer 9 defined the following probable lengths from the weights of the billet:

36 VL +RL Bar 1 367 m yields Bar 2 314 m yields 3| VL RL Bar 3 362 m yields 36 VL RL Bar 4 335 m yields 33 VL RL Bar 5=3l8m 3lVL+RL yields The last but one multiple length of a bar must be shorter by at least one merchant length than the maximum multiple length and must be longer by at least one merchant length than the minimum permissible, length r in the cooling bed so that maximum possible deviations can be subtracted or added afterthe check measurement. I

The computer divides as follows:

Bar 1: lst multiple length 9 VL )All in first 2nd multiple length 8 VL )cold shear 3rd multiple length 9 VL )batch 4th multiple leggth =10 VL RL Total 36 VL RL It is found for bar 2 that the maximum multiple length in this case can be only 9 VL since the minimum multiple length must be at least 7 VL and the last but one multiple length must be at least 8 VL. Bar 2 is therefore divided as follows:

The" first two multiplelengthsofthbarfi are re quired for the second cold shear batch. They must therefore not be longer than 9 VL. Thereafter the computer 9 must set the maximum multiple length again to VL because in the event of an excess quantity and given a maximum multiple length of 9 VL, the computer could not add anything to the last but one multiple length, which would already be 9 VL.

Bar 3: lst multiple length 9 VL Second cold 2nd multiple length 8 VL shear batch 3rd multiple length 9 VL Third cold 4th multiple length =10 VL RL shear batch Total 6 VL RL The division of bar 4 will be initially calculated as follows:

Bar 4: lst multiple length 7 VL 2nd multiple length 7 VL Third cold shear batch 3rd multiple length 9 VL travels in this way through the cold shear silt the hold up is more prolonged, the computer will re-calculate the division of the subsequent bars.

For very long merchant lengths (for example 24 m), 5 it is advantageous to distribute the discard length over the last two multiple lengths in order to minimize the cooling bed overhang which is required for the discard lengths.

We claim: 1. A method of dividing rolled lengths of stock into merchant lengths, comprising:

dividing each said rolled length of stock into a number of multiple lengths; cooling said multiple lengths in a cooling bed; collecting into batches said multiple lengths from a number of said rolled lengths of stock; and dividing said batches into said merchant lengths and at least one discard length; at least the last one of said multiple lengths being 4th multi le len =l0 VL RL )Fourth cold shear batch iotal v33 VL RL g On reachingbaFSItlTeYSmpYiEr cTs covemiat a gain only one maximum multiple length of 9 VL can be formed..l-lowever, the division of bar 4 must be recalculated because the last multiple length of bar 4, which together with the multiple lengths of bar 5, forms thefourth cold shear batch, had already been set to 10 VL RL. Bar 4 is therefore divided as follows:

Bar 4: lst multiple length 5* V 2nd multiple length 9 VL Third cold shear batch 3rd multiple length 8 VL 4th multiple length 9 VL RL )Fourth cold shear batch Total 33 VL RL Bar 5 is divided as follows: and all said multiplelengths respectively not greater than or less than the maximum or minimum B 5' length permitted by said cooling bed.

length 7 g 2. A method as claimed in claim 1, wherein the last 2nd multiple length 7 VL All in but one or the last but one and last but two said multi- 3rd multiple length 8 VL fmmh ple lengths are made shorter by at least one said mer- Shea, batch chant length than said longest lntegral multiple length I 4th mu lrtiplel length =9 VL +RL in the respective batch, and wherein the end of each ota ln this way the division of the entire charge is piel culated by the computer immediately after the billet weight is measured upstream of the furnace. The manner in which a bar is to be divided is therefore defined long before it is rolled. The computer therefore has sufficient time to re-calculate the division of a bar, if necessary, as shown by the example of bar 4.

Bars which are rejected and removed due to defects are treated as though they had not been removed if there is only a short hold up; that is to say the respective cold shear batch is only incompletely filled and said rolled length o f stock is sensed prior to cutting off said last but one or said last but one and last but two multiple lengths, said sensing being used to calculate the deviation of the actual rolled length from the calculated rolled length, such deviation being used torecalculate the lengths of said last but one or said last but one and last but two multiple lengths when they are cut off.

3. A'method as claimedin claim 1, wherein the discard length of a whole said rolled length of stock is distributed over two said multiple lengths.

4. A method as claimed in claim 2, wherein the discard length of a whole said rolled length of stock is distributed over two said multiple lengths. 

1. A method of dividing rolled lengths of stock into merchant lengths, comprising: dividing each said rolled length of stock into a number of multiple lengths; cooling said multiple lengths in a cooling bed; collecting into batches said multiple lengths from a number of said rolled lengths of stock; and dividing said batches into said merchant lengths and at least one discard length; at least the last one of said multiple lengths being equal to an integral multiple of said merchant length plus a discard length and the remainder of said multiple lengths being equal to an integral multiple of said merchant length, said multiple length which includes said discard length being longer by said discard length than the longest integral multiple length in the respective said batch, and all said multiple lengths being respectively not greater than or less than the maximum or minimum length permitted by said cooling bed.
 2. A method as claimed in claim 1, wherein the last but one or the last but one and last but two said multiple lengths are made shorter by at least one said merchant length than said longest integral multiple length in the respective batch, and wherein the end of each said rolled length of stock is sensed prior to cutting off said last but one or said last but one and last but two multiple lengths, said sensing being used to calculate the deviation of the actual rolled length from the calculated rolled length, such deviation being used to re-calculate the lengths of said last but one or said last but one and last but two multiple lengths when they are cut off.
 3. A method as claimed in claim 1, wherein the discard length of a whole said rolled length of stock is distributed over two said multiple lengths.
 4. A method as claimed in claim 2, wherein the discard length of a whole said rolled length of stock is distributed over two said multiple lengths. 